Pouring temperature-dependent tensile properties of squeeze cast magnesium alloy AJ62

Abstract

For advanced engineering design and manufacturing of light integrity magnesium automotive applications, it is critical to understand the effect of cross section thicknesses and metal pouring temperatures on mechanical properties of squeeze cast magnesium alloys. In this work, cylindrical coupons of magnesium alloy AJ62 with a diameter of 0.10 m and cross section thicknesses of 0.02 mm squeeze cast under an applied pressure of 60 MPa and with various pouring temperatures of 680, 700 and 720 °C. The results of tensile testing indicated that the mechanical properties of squeeze cast AJ62 alloy including yield strength (YS), ultimate tensile strength (UTS) and elongation (Ef) improved as the metal pouring temperatures decreased. A reduction in the pouring temperature from 720 to 680 °C increased the UTS to 179.6 from 126. 1 MPa, the YS to 144.6 from 91.4 MPa, and the ef to 3.6% from 1.3%. The mircrostruecture analyses show that the low pouring temperature were favourable for the refinement of dendritic structure and the formation of the continuous network of eutectic intermetallics along the dendrite boundaries. The refine dendritic structure and the massive presence of eutectic intermetallics should be responsible for the improvement on the tensile properties of the squeeze cast AJ62 alloy.